Boiler furnace



E. LU NDGREN BOILER FURNACE July 1, 1930.

Filed Feb. 17, 1925 2 Sheets-Sheet 1 A TTORNEKS I July 1, 1930. E. LUNDGREN 1,769,744

BOILER FURNACE Filed Fei. 17, 1926 2 sheets-sheet 2 52 T 5 if? M ,5 A; a v

'* ATTORNEYS Patented July 1, 1930.

UNITED, STATES PATENT OFFICE BUSTION ENGINEERING CORPORATION, OF NEW YORK, N.. Y., A CORPORATION OF DELAWARE BOILER FURNACE Application filed February 17, 192e. Serial m. 88,756.

This invention relates to boiler furnaces and is especially useful where the fuel to be burned is in finely divided form such as pulverized fuel.

One of the primary Objects of the invention is to greatly increase the capacity of a boiler of the cross drum type without materially increasing the size of the installation.

By my invention I propose bya novel arrangement of a cross drum boiler and a combustion chamber therefor to convert an ordinary cross drum boiler installation into a high capacity boiler installation, or construct a new installation from parts heretofore used in constructing the standard forms of boilersof this class.

The invention is particularly useful, al though not necessarily restricted tc, the converting of Babcock and Vtilcox boilers 1n connection with which it will be described. Other objects and advantages of my in vention will be set forth hereinafter as they will bemore' readily understood in cor? nection with the description of the invention.

How the foregoing, together with such other objects as may be incident to my in vention, are realized is illustrated in preferred form in the accompanying drawings, wherein- Fig. 1 is a vertical section through a boiler-furnace embodying the preferred form of my invention. r

Fig. 2 is a plan section taken substantially on the line ofFig. ,1, and

Fig. 3 is a fragmentarysection taken substantially on the line 3-3 of Fig. 1.

Referring now to the drawings and particularly to Fig. 1, it will be seen'that 1 take a boiler of the cross drum type and preferably drop the two banks of tubes A,

I with their front and rear header (1. and b respectively, well below the cross drum B, and that a combustion chamber C is provided between the banks of tubes and the drum. The headers a and b, of which there is one front and one rear for each vertical row of the tubes A, may be of any standard form, either straight or sinuous.

The side walls 4 and 5 are formed of sub-.

stantially horizontal finned tubes 6, connected into the vertical headers 7 and 8, the headers 7 being connected with the drum ]3 by means of downcomers 9 and the headers 8 being connected with the drum B by the upconiers 10, headers 11, and upcomers 12. The rear wall 13 is formed of shielded tubes 14-, which tubes connect the upper rear headers b of the bank of tubes A with the drum B. The tubes is are in this instance shielded by means of metallic blocks 15 which may be secured in position in any suitable manner. Thus it will be seen that these tubes may act as downcomers from the drum B to the rear headers b of the banks of tubes because the shielding thereof holds them at a lower temperature than the tubes A. In order to further insure adequate water flow to the headers b I also provide tubes 16 connecting the drum B with the lower portion of the headers 17 just mentioned, which tubes are shown outside of the combustion chamber. The front wall 17 of the combustion chamber C is formed of finned tubes 18 which connect the upper front headers a with the cross header 19, said tubes being upcomers. The top wall 20 is formed of finned tubes 21 which connect the cross header 19 with the drum B, said t'ubes being upcomers. The tubes A are marginal of the bottom of the combustion space, and it is pointed out that by virtue of the spacing of these rows of tubes passages are provided for the burnt products of combustion'to pass through to the ofitake 22, as well as any gravitating particles which may be removed from the settling chamber 23 through the tubes are connected by the finned upcomer EDWIN LUNDGREN, OF FREDERICK, MARYLAND, ASSIGNOR-TO INTERNATIONAL COM- Q I 27 and the headers thereof are connected by the finned downcomer tubes 28. In the particular arrangement shown in the drawings I have shown a greater number of tubes in the bank of tubes above the I superheater 26 than in the bank of tubes the temperature of the superheat may be decreased or increased by employing either tion it is pointe a greater number or a lesser number of tubes above the su rheater. In this connecout that the temperatureof the combustion air preheater 29 located in the waste gas stack 30 may also be varied by changing the number of tubes in thebanks.

The manner of introducing the fuel and combustion air to the combustion chamber to roduce violent and intense combustion wilPnow be described.

At the four corners of the boiler-furnace I have provided the burner nozzles 31 which deliver the pulverized coal in the combusthat I am enabled to (not 'tted produces a violentl combustion chamber cross sectionall ,withthe exception of the corners, where t e fuel is admitted, the fuel and flame stream descending'downwardly with the axis of the vortex substantially vertical. The preheated combustion air increases the furnace temperature. head and since the combustion chamber is dednedby water tubes exposed to radiant heat there is a very rapid transfer of heat. r I

The products of combustion are drawn through the banks of tubes under the influence of the stack draft whereby the banks of tubes are subjected to the hot ases, the upper tubes, however, being expose to radiant heat. v From the foregoing,

greatly increase the capacity of a cross'drum boiler installation by so converting it into a boiler furnace, and this without materiall increasing the size of the original insta lation. twill be noted that the length of travel of the steam and water leavin the headers a iacomparatively short, and t us, although tion chamber in converging streams tangent' ongitudinal axis of 2. I preferably introduce air' the coal and highly pre- .it will apparent the tubes 18 and 20 are subjected to extremely hi h temperatures, there are neither circulation nor tube difiiculties encountered.

While I have shownand described mVinvention as converti a Babcock and i1- cox cross drum boi er, it is to be understood that the advantages to be had through the practice of my invention ma be had b converting other boilers c ass.

What I claim is of this general 1. A boiler furnace comprising in combination a boiler of the cross drum t having an upper drum, a bank of substantially horizontal tubes, and headers into which the tubes are connected, said bank of tubes and said headers being below the level of the drum, a combustion chamber substantially intermediate the level of the drum and said bank of tubes, means for introducin fuel and air under conditions to low said bank of tubes for drawing of the products of combustion, said combustion chamber including side walls formed of substantially horizontal water tubes, at rear wall horizontal tubes, and front and rear headers y into which the tubes are connected, said bank of tubes and said headers being below the level of'the drum,,a combustion chamber substantially intermediate the level of the drum and said bank of tubes,"means for introducing fuel and air under conditions to produce violent and intense combustion, and an ofl'take below said bank of tubes for drawing of the products of combustion, said combustion chamber including side walls formed of substantially horizontal water tubes and their headers connected into the circulation of the aforesaid boiler a rear wall formed of shielded water tubes connecting the near headers of the aforesaid bank of tubes and the drum, a front well formed of finned water tubes connecting the front headers of said bank of tubes and a headerthereabov and a top wall formed of substantially tubes connecting the last mentioned header and the drum, said bank of tubes being marginal of the bottom of the combustion s ace.

3. The combination with a boiler o the cross drum type havin an up r drum, a bank of tubes inclined rom the grizontal,

and front and rear headers into which the,

roduce VlOlGIlt. and intense combustion, an an ofl'take beorizontal finned watertubes are connected, said bank of tubes and said headers being below the level of the drum, of a combustion chamber substantial.- ly intermediate the level of the drum and m said bank oftubes, comprising side walls formed of tubes similarly inclined to the tubes of said bank, front and rear headers for said tubes, upcomers connecting the front headers withthe drum, downcomers w connecting the rear headers with the drum, a front wall formed of tubes connecting the front headers of the banks of tubes with a header thereabove, a top wall formed of tubes connecting the last mentioned header with the drum, a rear wall formed of tubes connecting the drum-with the rear headers of the banks of tubes, still other tubes connecting the drum with said rear headers; suitable sheathing for the boiler furnace; means for introducing fuel to be burned in suspension in said combustion chamber, and an ofitake below the banks of tubes for drawing off the products of combustion.

4. The combination with a boiler'of the 5 cross drum type having an upper'cross drum,

a bank of substantially horizontal tubes below the level of the drum, and front and rear headers into which said tubes are connected; of a combustion chamber substantially intermediate the level of the drum and said bank of tubes, said combustion chamber including side walls formed of water tubes connected in circulation with the cross drum boiler, a rear wall formed of water tubes connecting the rear headers of said bank of tubes'with said cross drum, a front wall formed of water tubes connecting the front headers of said bank of tubes with a header thereabove, and a top wall formed of up- 40 fiow water tubes connecting said last mentioned header with said cross drum; said last mentioned header being located below the level of said cross drum; and means for admitting fuel, into the combustion chamber to be burned in space.

In testimony whereof I have hereunto signed my name.

, EDWIN LUNDGREN. 

